Developing Roller Silicon Compound Surface Layer Toner Release

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Solution Overview

Problem

Developing rollers with resin coating layers containing nitrogen exhibit strong tackiness, leading to toner deposition and fusion-bonding issues, which degrade image quality and shorten the lifespan of the roller, while elastic layers can bleed low-molecular-weight substances affecting image quality and drum life.

Innovation Solution

A developing roller with a silicon compound surface layer containing Si, N, C, and H, specifically formulated to inhibit low-molecular-weight substance bleeding, efficiently charge toners, and maintain superior toner-releasing properties, comprising a mandrel, an elastic layer, and a silicon compound film surface layer with controlled elemental abundance ratios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a resin coating layer containing nitrogen is used in the surface layer of the developing roller to efficiently impart high electric charge to negatively chargeable toner, then the charging efficiency is improved, but the surface shows strong tackiness causing toner deposition and fusion-bonding which degrades image quality and shortens roller lifespan

Engineering Contradiction:

Improvecharging efficiencyVSAvoidroller lifespan and image quality

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The surface layer is designed with non-uniform composition and structure, creating different local properties: the nitrogen-containing region provides charging efficiency while the fluorine-containing region provides low surface energy and reduced tackiness, preventing toner fusion-bonding

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The surface layer is formed as a composite material containing both nitrogen-containing compounds (for charging) and fluorine-containing compounds (for reducing surface energy), combining the benefits of both materials to achieve simultaneous charging efficiency and toner release capability

Inventive Principle:

Principle #40Composite materials

2Shape

If an elastic layer is provided in the developing roller to secure nip width with the photosensitive drum, then the nip width is improved, but low-molecular-weight substances bleed out to the surface affecting image quality and drum life

Engineering Contradiction:

Improvenip widthVSAvoidlow-molecular-weight substance bleeding

Core Design Contradiction:

ShapeVSObject-generated harmful factors

Solution Approach 1:

The surface layer acts as an intermediary barrier between the elastic layer and the photosensitive drum, preventing low-molecular-weight substances from the elastic layer from bleeding through to the drum surface while maintaining the nip width function

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

A thin film surface layer is applied over the elastic layer to seal and contain the low-molecular-weight substances within the elastic layer, preventing their migration to the surface while maintaining the flexibility and nip width of the elastic layer

Inventive Principle:

Principle #30Flexible shells and thin films

3Force

If the surface layer has strong tackiness to deposit toner, then the toner adhesion is improved, but the toner gradually deteriorates and fusion-bonds to the surface degrading image quality

Engineering Contradiction:

Improvetoner adhesionVSAvoidimage quality

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The surface energy parameters of the surface layer are precisely controlled by adjusting the composition and ratios of nitrogen-containing and fluorine-containing compounds, achieving an optimal balance between toner adhesion (requiring some tackiness) and toner release (requiring low surface energy)

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents low-molecular-weight substance bleeding, ensures high-quality image formation, and extends the roller's lifespan by maintaining optimal toner charging and releasing properties, even after prolonged use.

Implementation Method 1

The developing roller is required to have a function of imparting an adequate frictional charge to the toner

Methodology Applied

Scientific EffectTriboelectric effect: Triboelectric Effect

Implementation Method 2

a resin layer containing nitrogen positively charges when being actually used, and the surface shows strong tacking (stickiness) properties, so that a negatively chargeable toner is apt to deposit on the surface of the resin layer

Methodology Applied

Scientific EffectBarrier effect:

Data Source

PatentEP2159649B1Developing roller, and electrophotographic process cartridge and electrophotographic image forming apparatus comprising the developing roller

Publication Date: 2013.12.25 CANON KK

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AI summary

The prevent invention relates to a developing roller having a surface layer which can effectively inhibit the bleed of a low-molecular-weight component from an elastic layer, can efficiently impart a high electric charge to a negatively chargeable toner, and is excellent in toner-releasing properties. The developing roller has a mandrel, at least one layer of an elastic layer provided on the mandrel and a surface layer provided on the elastic layer, carries and conveys a toner, and develops an electrostatic latent image on an opposing photosensitive member with the toner, and the surface layer comprises a silicon compound film containing Si, N, C and H having specific total abundance of the existing elements Si, N, C and H, and specific abundance ratios N/Si, C/Si, and H/Si.